Karl Rove is under no illusion that leaving the White House will end the congressional investigations into his activities. "I'm Moby Dick," he said, "and they're after me."

In an interview after announcing his resignation today, Rove said he is leaving after 6-1/2 years in the White House because he genuinely wants to spend more time with his family and scoffed at the idea that the probes played any role in his decision.

"The people who are saying that are suggesting that if the rooster crows enough and the sun comes up, it's because of the rooster," he said. "I'm leaving on my own terms and I'm leaving with a clear-eyed realism that this isn't going to mean fewer investigations or subpoenas or weird comments by members of the Democratic caucus. These guys are obsessed with me and they think I'm a convenient and easy target to play to their base and raise money."

Even when he returns to Texas, Rove said he expects that he will be under attack for his role advising Bush. "I realize that some of the Democrats are Captain Ahab and I'm the great white whale," he said. "I noticed the other day some Democratic staffers were quoted calling me the big fish. Well, I'm Moby Dick and they're after me."

Democratic-led congressional committees are looking into Rove's involvement in the firings of U.S. attorneys last year as well as the series of political briefings conducted at government agencies and the use of Republican National Committee email accounts by White House officials.

Some Democrats cast Rove's departure as a response to the investigations. "The list of senior White House and Justice Department officials who have resigned during the course of these congressional investigations continues to grow, and today Mr. Rove added his name to that list," said Senate Judiciary Committee Chairman Patrick J. Leahy (D-Vt.).

Just two weeks ago, citing the president's invocation of executive privilege, Rove defied a congressional subpoena and refused to appear at a hearing looking into the e-mail dispute. Some Democrats have suggested that former presidential aides have a weaker legal claim to refuse to respond to subpoenas under executive privilege, but the White House says the privilege still covers them whether they are still employed there or not.

In the interview, Rove criticized the Democrats for pursuing him and said their investigations have diminished their public support. "There is a reason," he said, "why the Congress has gone from high standing after the '06 election to being less popular than the president."

Still, Rove said he, too, was surprised that he was leaving now. Many of his colleagues had long assumed that he would stay until the end of the Bush presidency in January 2009.

"So did I," he said. "I wanted to. But I just can't. About a year and a half ago, it became apparent talking to my family that there are things happening, that it was time to go."